Former Arizona Republican Rep. Jim Kolbe is fed up with Maricopa County Sheriff Joe Arpaio’s participation in the so-called “birther” movement, and with his claims that President Obama’s birth certificate is a forgery.

According to Kolbe, who served as a congressman from 1985 to 2007, “It would be easy to dismiss Sheriff Arpaio as a clown or buffoon, but his policies and actions have become a major embarrassment to our state.”

On Thursday Arpaio held a press conference in Phoenix to announce the results of an investigation conducted by a five-member “cold case posse” that he had appointed to probe conspiracy theories about Obama’s birth.

At the press conference, Arpaio said there was “probable cause” to suspect forgery, and said that the “perpetrators” of two alleged felonies — forgery and fraud — must be “brought to justice.” He also said that he wouldn’t be dropping the investigation.

The 79-year-old sheriff, who is the chief law enforcement officer in the 4 million-person county, “has polarized people over race and immigration instead of seeking to find responsible solutions to difficult problems,” said Kolbe.

“He has embroiled Maricopa County taxpayers in costly litigation and lawsuits,” said the former congressman, and “he has brought down Justice Department investigations into the operations of his sheriff’s department.”

The Justice Department announced in December that it had documented mistreatment of Hispanic prison inmates in the county and found that hundreds of cases of alleged sexual assaults hadn’t been investigated. Arpaio has also been an object of praise and scorn for forcing male prisoners to wear pink underwear, and for reinstating chain gangs.

Kolbe told TheDC that Arpaio’s allegations about Obama’s birth certificate “puts him firmly on the side of a group that is short of one percent of all Americans who, despite the irrefutable evidence to the contrary, continue to believe President Obama was not born in the United States.”

The eleven-term former congressman suggested that “Sheriff Arpaio needs to drop these crackpot ideas and tend to the business of cleaning up his own department.”